Many different devices, particularly boom-supportable devices, have been developed over the years for lifting and moving materials such as dirt, rocks, broken materials and the like. Such equipment is used in many different operations. Vehicles of various kinds frequently suspend such lifting and moving devices on the distal ends of booms which are used to manipulate the devices in various ways to lift, remove, and later release the materials which they carry.
For various reasons, it is often desirable to lift and move large rocks, broken pieces of concrete, broken pieces of asphalt, or the like without carrying with them dirt, sand, gravel, and other particulates. Such "clean" lifting and movement is useful, for example, in removing broken concrete or asphalt pieces of the type frequently created by the breaking up of roadbeds, sidewalks, and the like, when recycling of the removed material is anticipated. Such removal, without undesired particulates, allows later recycling to be carried out with a minimum of impurities. There are many other reasons for wanting to "cleanly" remove large rocks, broken concrete, broken asphalt, and the like.
The equipment of the prior art frequently does not perform such removal operations adequately or has disadvantages making its use undesirable or impractical. This is often the case for the small contractor who does not wish to acquire expensive equipment for the task.
In some cases, space limitations and other operational constraints can limit the maneuverability of lifting and moving equipment. This makes "clean" lifting and moving of large pieces from the ground to another location more troublesome than it would otherwise be. For example, in removing large pieces of broken asphalt or broken concrete from a driveway, or pieces of broken concrete from a sidewalk, a boom-supported lifting device sometimes cannot easily pick up and deposit such pieces cleanly because the movement of the boom and the position of the vehicle from which the boom extends are limited by the surroundings. Adjustment of scoop-like digging devices to accommodate such limitations and constraints is frequently time-consuming or impossible.
In some cases, devices which would otherwise provide a grid allowing "clean" lifting and movement of large pieces is susceptible to bending and distortion of certain parts by virtue of the heavy forces exerted on the devices by large and irregularly shaped stones, concrete or asphalt pieces, and the like. Such bending and distortion tend to make such equipment less useful or non-functional. Replacement of such equipment may be expensive and time-consuming.
In short, there is a need for improved equipment for "clean" lifting and moving large pieces, such as rocks, broken concrete and broken asphalt.